Fixes #1823

Documentation of security_groups argument doesn't mention VPC
Merge pull request #1824 from twork-veracode/develop

Update auto scaling documentation. Fixes #1824, #1823.
Merge pull request #1831 from garnaat/develop

Fixing region endpoints for EMR
sqs.message: Raising an exception in decode() should not abort parsing

Since AWS seems to return Body before ReceiptHandle, raising an exception in decode() will abort processing before the receipt handle is read.

This is a problem, because there's no way to dequeue the message without the handle.

Instead, wait to invoke decode() until parsing is finished.
Add support for new EMR APIs
Merge pull request #1836 from danielgtaylor/emr-update

Add support for new Elastic MapReduce APIs
Add generated documentation for route53/zone
Remove generated documentation for implenentation classes route53/exception and route53/hostedzone
Modify EMR add_jobflow_steps to return a JobFlowStepList with a list of step ids, part of the latest EMR API updates.
Merge pull request #1835 from bodylabs/decode_sqs_message_after_parsing_finishes_2

Raising an exception in SQS message decode() should not abort parsing. Fixes #1835, #1833.
Add a basic test for new add_jobflow_steps behavior.
Test a second item to make sure the list is properly processed and not just the first item is returned.
Merge pull request #1838 from danielgtaylor/jobflow-steps

Modify EMR add_jobflow_steps to return a JobFlowStepList. Fixes #1838.
Restore exception documentation
Update README version / release date
Merge pull request #1837 from phickey/develop

Generate docs for route53/zone, remove docs for route53/hostedzone. Fixes #1837.
Fixed parameter order in test

Params were around the wrong way. Test was passing coincidentally.
Issue #1843: replace correct ACL association

Fixes problem where an ACL is associated with multiple subnets, and
associate_network_acl replaces a random other subnet's association
to the ACL.
relay the error code and message from Amazon to application
Added tests for the Cloudsearch changes. Finishes #1842.
Shuffled the test to unit, since it's not actually hitting the service.